Re: Suspend/resume regressions on Lenovo S10-3

[Deepthi Dharwar <deepthi@linux.vnet.ibm.com>]

On 05/28/2012 07:23 AM, Dave Hansen wrote:

> I have a Lenovo S10-3 Atom netbook.  It's always had some amount of
> trouble working with the intel_idle driver, so I usually compile that
> out an use the acpi one.  However, just after 3.1, suspend/resume broke.
>  'echo mem > /sys/power/state' would hang before suspending.  I bisected
> it down to the commits around:
> 
> 	e978aa7d7d57d04eb5f88a7507c4fb98577def77 / v3.1-1-ge978aa7
> 
> by Deepthi.  But, current mainline (v3.4-07644-g07acfc2) hangs with a
> different symptom: it suspends, but hangs on resume from suspend.  I
> think _that_ delta in the behavior was caused by:
> 
> 	3439a8da16bcad6b0982ece938c9f8299bb53584
> 
>         ACPI / cpuidle: Remove acpi_idle_suspend (to fix suspend
> 		regression)
> 
> It's a bit of a pain to bisect these two different things in parallel.
> I was trying to tell git bisect 'good' on working suspend/resume, 'bad'
> on the hang during resume, and 'skip' on the hangs _during_ suspend.  83
> kernels in, I'm not sure that's working very well. :)
> 
> Deepthi, do you have any idea why your patches broke me in the first
> place?  Perhaps we should fix that regression first before we go on and
> try to figure out what changed to let it suspend again, but break later.


Hi Dave,

Sorry about my patches breaking your suspend-resume.

I, basically tried out building and booting 3.1 kernel with 
my patch set to reproduce the failure. I could clearly
see suspend not happening. It turns out to be 
a bug with my first patch in global registration
series submitted earlier.

e978aa7d7d57d04eb5f88a7507c4fb98577def77 / v3.1-1-ge978aa7

The following patch, fixes the suspend issues
seen on my laptop due to earlier cpuidle cleanup 
(Lenevo T420 booting with acpi_idle enabled). 
Can you please give this a try
on top of my patch set (without Rafael's fix) 
and see if it fixes the problem for you. 
I am not reverting acpi_idle_suspend flag and 
hopefully it should resume fine too. 

---

This patch fixes suspend-resume issue seen in the kernel 3.1
series using acpi_idle_driver because of cpuidle global 
registration cleanup.
Here, when acpi_idle_suspend flag was set ( during suspend)
the interrupts were not getting enabled in acpi_idle_enter_bm()
routine which was causing the system to hang.


Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>

---
 drivers/acpi/processor_idle.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 24fe3af..6e35293 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -895,8 +895,9 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 	if (unlikely(!pr))
 		return -EINVAL;
 
-
 	if (acpi_idle_suspend) {
+		local_irq_disable();
+		local_irq_enable();
 		cpu_relax();
 		return -EINVAL;
 	}

Cheers,
Deepthi